Related Experiment Video

Updated: Jul 5, 2026

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43
06:06

Constructing Mutants in Serotype 1 Streptococcus pneumoniae strain 519/43

Published on: September 11, 2020

Serotype replacement and multiple resistance in Streptococcus pneumoniae after the introduction of the conjugate

Robertino Mera1, Linda A Miller, Thomas R Fritsche

  • 1GlaxoSmithKline, Research Triangle Park, North Carolina, USA. robertino.mera@gsk.com

Microbial Drug Resistance (Larchmont, N.Y.)
|May 22, 2008
PubMed
Abstract

Insights

The pneumococcal conjugate vaccine (PCV7) led to a decrease in vaccine-type serotypes, but nonvaccine serotypes increased and acquired multidrug-resistance (MR). This shift highlights the need to monitor evolving antimicrobial resistance patterns in Streptococcus pneumoniae.

Area of Science:

  • Microbiology
  • Epidemiology
  • Vaccinology

Background:

  • The heptavalent pneumococcal conjugate vaccine (PCV7) was introduced in the U.S. in 2000.
  • PCV7 significantly impacted pediatric Streptococcus pneumoniae serotype prevalence.

Purpose of the Study:

  • To evaluate changes in pneumococcal serogroup prevalence and multidrug-resistance (MR) over time.
  • To assess the impact of PCV7 on antimicrobial resistance patterns.

Main Methods:

  • Analysis of 704 U.S. Streptococcus pneumoniae isolates from before (1998-1999) and after (2003-2004) PCV7 introduction.
  • Evaluation of serotype prevalence and resistance to five antimicrobial classes.
  • Definition of MR as resistance to two or more antimicrobial classes.

Main Results:

  • PCV7 serotype prevalence decreased from 68.5% to 29.3% post-vaccine.
  • Nonvaccine (NV) serotypes, particularly 19nonF, increased significantly.
  • NV serotypes were more likely to acquire MR, contributing to unchanged overall MR rates despite PCV7 use.

Conclusions:

  • A shift from PCV7 to NV serotypes occurred, influenced by herd effects.
  • NV serotypes are acquiring multidrug-resistance proportionally to their increased prevalence.
  • Continuous surveillance is crucial to monitor evolving antimicrobial resistance in pneumococcal populations.

More Related Videos

Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination09:11

Capsular Serotyping of Streptococcus pneumoniae by Latex Agglutination

Published on: September 25, 2014

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction04:25

Capsular Serotyping of Streptococcus pneumoniae Using the Quellung Reaction

Published on: February 24, 2014

Related Concept Videos

Mechanism of Antibiotic Resistance in MRSA01:25

Mechanism of Antibiotic Resistance in MRSA

Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
Atypical Pneumonia01:14

Atypical Pneumonia

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...
Conjugation01:19

Conjugation

Conjugation is a form of horizontal gene transfer that primarily occurs in bacteria and some archaea, promoting genetic diversity and adaptation. Bacteria can acquire resistance genes through conjugative plasmids, allowing them to survive antibiotic treatments that would otherwise be lethal. This process involves direct contact between cells through specialized structures such as the sex pilus and is mediated by conjugative plasmids, including the F (fertility) factor.Conjugation requires...
Streptococcal Pharyngitis01:27

Streptococcal Pharyngitis

Streptococcal pharyngitis, commonly known as “strep throat,” is an acute infection of the oropharyngeal tissues caused by the Gram‑positive Group A Streptococcus (Streptococcus pyogenes). Transmission occurs primarily through respiratory droplets expelled during coughing, sneezing, or talking.Mechanisms of Host Entry and Immune EvasionUpon entering the host, S. pyogenes adheres to the mucosal epithelial cells of the pharynx via surface proteins, notably lipoteichoic acid and the antiphagocytic...
Pneumonia I: Introduction01:29

Pneumonia I: Introduction

Pneumonia is an infection of the lower respiratory tract that leads to inflammation of the lung parenchyma, often resulting in the accumulation of inflammatory exudate in the alveoli and airways. Unlike the watery, low-protein fluid exudate in pulmonary edema, the exudate in this case is a thick fluid rich in immune cells, proteins, and debris produced during infection and inflammation.This impairs gas exchange and can lead to consolidation of lung tissue. The infection may be caused by a...
Viral Recombination00:57

Viral Recombination

Cells are sometimes infected by more than one virus at once. When two viruses disassemble to expose their genomes for replication in the same cell, similar regions of their genomes can pair together and exchange sequences in a process called recombination. Alternatively, viruses with segmented genomes can swap segments in a process called reassortment.